1. Field of the Invention
The present invention relates to a probe apparatus having a burn-in test function for performing thermal and electrical screening of a semiconductor wafer.
2. Description of the Related Art
Integrated circuit (IC) chips are formed on a semiconductor conductor wafer by processes, e.g., film deposition, and cut and packaged, thereby manufacturing integrated circuits. In this semiconductor device manufacturing process, conventionally, the electrical characteristics of semi-finished semiconductor devices are tested and determined in the state of a semiconductor wafer. Only those determined as non-defective devices as the result of the test and determination are packaged and subjected to the subsequent processes, thereby improving the productivity.
A potential defect is sometimes involved in an IC chip due to a film deposition defect during the process. After such an IC chip is packaged, this defect may appear to cause a trouble at a high probability. Therefore, the defect must be caused to appear in advance by accelerating the stress under severe conditions. For this purpose, a stress load test (screening) called a burn-in test is performed.
Conventionally, the burn-in test is performed by mounting a packaged IC chip in a stress loader, heating or cooling the IC chip, applying an overvoltage or an inspection pulse smaller or larger than the rated pulse to the terminals of the IC chip, and measuring, for example, currents flowing in the respective terminals. An idea of performing such a burn-in test by using a probe apparatus has not conventionally existed.
When the burn-in test is to be performed in the manner as described above, the packaged IC chip must be mounted in the stress loader and removed after the test, resulting in a cumbersome operation. Then, the time required for the entire burn-in test process is prolonged, partly interfering with an increase in throughput. Also, an IC chip whose defect becomes apparent at this time point has already been packaged. Even if the defect of this IC chip is small, it is difficult to repair this IC chip.
Furthermore, when the IC chip becomes defective during the burn-in test, short circuiting occurs in the IC chip to flow an overcurrent. Then, the IC chip is burnt and cannot be repaired.